挡土墙土压力非线性分布的计算方法研究

A Calculating Method of Non-Linear Earth Pressure Behind Retaining Walls

基于数学方法对斜单元体进行力和力矩的平衡分析,得到了墙背粗糙且填土坡面倾斜情况下的土压力解析解,并进一步分析了填土坡面倾角对土压力的影响。对比分析表明:经典朗肯土压力理论可看作是解析解在墙背光滑、填土坡面水平情况下的特例;在填土内摩擦角一定时,挡土墙墙后滑动楔体的极限破裂角随着填土坡面倾角或墙土之间摩擦角的增大而减小。基于解析解得到的土压力分布呈现明显的非线性特征,且在填土面水平情况下挡土墙墙脚处的土压力为0,这与实测数据取得了很好的一致。分析还表明,随着填土坡面倾角的增大,墙脚处的土压力不再接近0反而越来越大。文中的求解方法还可进一步拓展至探求填土为粘性土情况下挡土墙上土压力的解析解。

Based on equilibrium analysis of forces and moment with inclined soil element, an analytical solution of earth pressure with inclined surface of fill and rough retaining wall was proposed, and the influence of slope angle of fill on earth pressure also was discussed. It is shown that the classical Rankine＇s earth pressure theory is a special case of the analytical solution with horizontal surface of fill and a smooth retaining wall. The results also show that the limiting rupture angle of a sliding-wedge behind a retaining wall decreased with increasing slope angle of fill or friction angle between soil and a retaining wall, with the settled value of the internal friction angle of fill. The non-linear character of earth pressure exhibited distinctly for the earth pressure along a retaining wall was obtained by an analytical solution. The value of earth pressure is 0 at the toe of retaining wall, consistent with the testing results. In addition, the value of earth pressure at the toe of the retaining wall will increase rapidly with increasing slope angle of fill. The analytical solution of earth pressure behind a retaining wall with fill of clay soils can be further studied with the investigative method we developed.